Publications

Validation of finite element models using experimental data with unknown boundary conditions proves to be a significant obstacle. For this reason, the boundary conditions of an experiment are often limited to simple approximations such as free or mass loaded. This restriction means that vibration testing and modal analysis testing have typically required separate tests since vibration testing is often conducted on a shaker table with unknown boundary conditions. If modal parameters can be estimated while the test object is attached to a shaker table, it could eliminate the need for a separate modal test and result in a significant time and cost savings. This research focuses on a method to extract fixed base modal parameters for model validation from driven base experimental data. The feasibility of this method was studied on an Unholtz-Dickie T4000 shaker and slip table using a mock payload and compared with results from traditional modal analysis testing methods. © The Society for Experimental Mechanics, Inc. 2012.

A series of modal tests were performed in order to validate a finite element model of a complex aerospace structure. Data was measured using various excitation methods in order to extract clean modes and damping values for a lightly damped system. Model validation was performed for one subassembly as well as for the full assembly in order to pinpoint the areas of the model that required updating and to better ascertain the quality of the joint models connecting the various components and subassemblies. After model updates were completed, using the measured modal data, the model was validated using frequency response functions (FRFs) as the independent validation metric. Test and model FRFs were compared to determine the validity of the finite element model.

A series of modal tests were performed to validate a finite-element model of a complex aerospace structure. Data were measured using various excitation methods to extract clean modes and damping values for a lightly damped system. Model validation was performed for one subassembly as well as for the full assembly to pinpoint the areas of the model that required updating and to better ascertain the quality of the joint models connecting the various components and subassemblies. After model updates were completed using the measured modal data, the model was validated using frequency response functions (FRFs) as the independent validation metric. Test and model FRFs were compared to determine the validity of the finite-element model.

Abstract not provided.